试论宏体植物的早期演化

概述了地史早期宏体植物化石的记录。从细胞群体到组织-器官构造有大约11 亿年的漫长进化史。蓝田植物群和庙河生物群标志着震旦晚期(大约7-5.4 亿年间)发生了宏体植物演化史上的一次大辐射,非矿化、弱矿化、和矿化的高级藻类出现。寒武纪发生了另一次辐射。非矿化藻类是最有发展前途的类群,可能直接导致了维管植物的出现。     

南秦岭淅川地区上石炭统周营组生物群特征

南秦岭淅川地区上石炭统周营组有多门类化石共生 ,类为晚石炭世的标准分子 ,菊石、腕足、珊瑚、双壳、腹足类多具泥盆纪生物群特征。岩石组合、岩性特征、层序特征、沉积环境演变及构造古地理、生态的综合研究表明 ,周营组为晚石炭世沉积地层 ,其内的晚石炭世、中晚泥盆世古生物组合是在有障壁的局限滞留盆地这一特殊的古地理和生态环境下形成和发展起来的 ,是南秦岭淅川地区特有的组合 ,不具有搬运再沉积的物质条件 ,不是搬运再沉积的结果。每一次海侵 ,海水的加深和有机质的富集 ,是周营组生物群得以发生和发展的有利条件。海水的退出、咸化和相对闭塞环境下食物的缺乏 ,是生物群绝灭 ,并很好保存埋藏的主要原因。     

Biota and Organic Matter in the Late Sinian and EarlyCambrian Black Rock Series of West Hunan andIts Significance for Metallization

A great amount of black rock series has been found in the Upper Sinian Members 2 and 4 of the Jinjiadong Formation, middle-upper Liuchapo Formation and the Lower Cambrian Xiaoyanxi Formation in West Hunan, which is associated with periodic sea-level changes. By the studies of relationships between the distribution and development of the biota and the abundance of Au, Ag, U, V, Ni, Mo and Cu in the Upper Sinian and Early Cambrian black rock series in Cili, Dayong, Yuanling, Xupu and Qianyang of West Hunan, central China, it has been revealed that the enrichment of Ag, V, and Mo is related with the development of multi-cell plants and vendotaenides, and that of Cu and Ni is related to flourishing of bacteria and shelly fossils. The black rock series in the study area contains abundant organic matter, among which the siliceous shale contains the highest TOC, amounting to 4.51-13.4%. All the values of the equivalent vitrinite reflectance (medium values) determinated with the IR-spectroscopic method in the a     

贵州关岭上三叠统瓦窑组中碳酸盐岩结核形成的生物作用

贵州省关岭县新铺乡附近的晚三叠世早期地层瓦窑组底部产具重大科学意义的关岭生物群。关岭生物群产出地层中伴有大量大型碳酸盐岩结核。这些结核中部都有植物茎干,结核内的海百合、双壳、菊石、牙形刺等生物化石含量明显高于结核周围的岩石,且有许多生物化石直接附着在植物茎干上。这类结核的形成,除化学沉积作用外,还有生物作用的影响。海百合、双壳类和菊石类栖息在植物茎干上营假浮游生活,随着栖息生物量和化学沉积物灰泥的增加,逐渐沉积在海底形成结核。     

The carbon isotopic ratio of atmospheric carbon dioxide at Tsukuba,Japan

To find out the secular and seasonal trends of the ¹³C value and CO₂ concentration in the surface air and the determination of the ¹³C in the atmospheric CO₂ collected at Tsukuba Science City was carried out during the period from July 1981 to October 1983. The monthly average of the ¹³C value of CO₂ in the surface air collected at 1400 LMT ranged from -7.52 to \s-8.45 with an average of -7.96±0.25 and the CO₂ concentration in the air varied from 334.5 l 1^-1 to 359 l 1^-1 with an average of 347.2±6.3 l 1^-1. The ¹³C value is high in summer and low in winter and is negatively correlated with the CO₂ concentration. In general, the relationship between the ¹³C and the CO₂ concentration is explainable by a simple mixing model of two different constant carbon isotopic species but the relationship does not always follow the model. The correlation between the ¹³C value and the CO₂ concentration is low during the plant growth season and high at other times. The observed negative deviation of the ¹³C value from the simple mixing model in the plant growth season is partly due to the isotopic fractionation process which takes place in the land biota.     

Sedimentological features and biostratigraphy of Jurassic/Cretaceous deposits in continental basins in Priamurie, Far East Russia

The paper describes the sedimentary features and biostratigraphy of the transitional Jurassic to Cretaceous deposits in the continental basins of Priamurie formed after the collision between the Siberian and North China blocks. In Upper Priamurie, the collision occurred in the late Early Jurassic as dated by the emplacement of the post-collisional granites (191Ma) . While in Lower Priamurie and West Priokhotie it could take place in the late Middle Jurassic on the basis of fossil evidence from an accretionary turbidite complex. This event reflected the environmental change from coastal-marine to alluvial plains, often boggy, where coals accumulated. The environmental change is in harmony with that of biota. Systematic study of floral and spores/pollen assemblages, particularly in the sections of interbedded marine and non-marine deposits, makes clear the chronostratigraphic succession of floral associations and shows the possibility of their application for subdivision and correlation of the continental deposits of Priamurie. The coastal-marine environment of the residual post-collisional sublatitudinal basins in the western part of Priamurie (Upper Amur and Dep basins) was replaced by the continental in the late Middle Jurassic and in the eastern part in the Berriasian-Valanginian ( Torom Basin) . Similar environmental change commenced in the submeridional rift basins: the Bureya Basin in the Callovian and the Partizansk Basin in the Hauterivian. Changes in ecosystems occurred frequently during theMiddle Jurassic-Neocomian, but the most substantial changes took place in the late Middle Jurassic and in the end of Late Jurassic.     

Organochlorine pesticides in marine environment of Quanzhou Bay, Southeast China

As one of the most important buildup of persistent organic pollutants （POPs）, organochlorine pesticides （OCPs） have received more and more attention. Samples including sediments, water and marine products were collected. In the lab, nineteen types of organochlorine pesticides were tested using GC-ECD following US-EPA 8080A method. In the top sediments, the concentration of HCHs was 0.1-3.08 ng/g and the concentration of DDTs was 3.53-75.83 ng/g. In the bottom sediments, the concentration of HCHs was 0.1-3.59 ng/g and the concentration of DDTs was 1.56-81.68 ng/g. The concentration ranges of HCHs and DDTs in sea water were 1.31-9.96 ng/L and 0.78-6.51 ng/L, respectively. And the concentration ranges of HCHs and DDTs in land surface water were 7.04-14.08 ng/L and 3.82-9.66 ng/L, respectively. The residual levels of HCHs and DDTs in marine product samples ranges from 0.1 to 0.6 ng/g and from 0.57 to 85.02 ng/g, respectively. In this thesis, discussions of DDTs and HCHs in sediment, water and marine product samples were made. The following are the main results and conclusions： A general decreasing trend was found from the inner to outer sectors of the Bay for both sediment and water samples. The distribution of OCPs depends greatly on the different properties pertaining to them. The topography, redox, hydrodynamic condition as well as other factors also play an important role in controlling the distribution and fate of OCPs.     

瓮安生物群中后生动物化石研究进展及问题讨论

贵州瓮安埃迪卡拉（震旦）纪陡山沱期磷酸盐化生物群具有生物多样性特征，包含有蓝菌、多细胞藻类、疑源类、后生动物休眠卵及胚胎、可疑的海绵动物、管状后生动物和微小两侧对称的后生动物等化石类型，是迄今为止全球保存最为完好的晚前寒武纪磷质化石库。瓮安陡山沱组磷质岩提供了早期生命从简单到复杂进化过程中的重要化石记录，展示了埃迪卡拉生物群出现以前早期多细胞生物的生命景观，为研究晚前寒武纪生物圈面貌提供了一个重要的埋葬学窗口。近来，通过醋酸浸解法，在贵州瓮安陡山沱期含磷地层中发现了大量疑似后生动物的实体化石（包含了所有已经报道的类型或与之相似的化石类型）新材料，为了解这些化石的内部构造特征，将一些化石包埋后制作了定向薄片。基于上述化石新材料，结合定向薄片的研究和前人的研究成果，本文详细介绍了瓮安生物群中后生动物化石研究的新进展和存在的问题。     

皖南地区震旦系古介形类化石的发现及其意义

皖南地区下震旦统蓝田组(相当于陡山沱阶)下部植物宏体藻层内发现古介形类化石是一个重大发现。它是已知古介形类产出的最低层位,将原初见于早寒武世地层梅树村阶底部下延至早震旦世地层陡山沱阶下部(时限前溯约130Ma)。文中根据古介形类化石的结构、构造、壳质及软体等特征,将其归于动物分类系统的Arthropoda—Crustacea—Ostracoida—Archaeostaidae—Sinogella(gen.nov.)—S.lantianensis(gen.et sp.nov.);并作为讨论Sinogella种族发生演化史的依据,认为在自然选择支配下古介形类历经具节肢—外套膜—几丁质外壳的重要发展阶段,其中尤以外套膜的出现最为重要,其功能是保护介虫躯干,继后,外套膜分泌几丁质外壳,形成新属种Sinogella lantianensis(gen.et sp.nov.)等。这些化石的发现为原称"蓝田植物群"更名为"蓝田生物群"提供了确凿的动物化石证据。